Yes it is a dream job and can pay big bucks. I'm at over 6 figures now but have been on this job more than a few years. The key to big bucks is not to take the job that pays huge, but to take the job that you will keep for many years. A 250K a year job you have for 2 months is not as good as a 85K/yr job you have for ten years. After a few years the owners should give you constant raises. Not because you NEED a raise but because YOUR WORTH MORE. Become an independent contractor and pick up your own health and life insurance so your credit history and employment is a constant.
Mainly think of when your 57 years old and still scrubbing decks with a brush in one hand and a bottle of Asprin in the other!! Get a college degree FIRST whippersnapper. It will make it easier to get a good position with a good boat over the other canditates who are just coming up with sea time but no degree. I wish I had an escape plan but luckily I'm holding up physically so I should last a few more years!
But to answer you original question after a few years work you should be well over 100k/year on any boat your on over 100'. For the best and latest snuggle up to someone at a crew agency and pick thier brain. Those of us out there driving boats are too darn busy to talk to other crew to find out what they are making. Oh, gotta go and wash the food stains off the teak decks.